The aim of this investigation is to examine the characteristics of the natural human salivary antibody response to S.mutans glucosyltransferase (GTF). We will study the parotid salivas from young adults for the presence of salivary antibody activity to GTF from serotype c strain S.mutans. The parotid salivary IgA of those with elevated parotid salivary levels will be examined for reaction with GTF from indigenous S.mutans as well as for the specificity of this response for GTF from other strains and serotypes. The salivary IgA responses from minor salivary glands and submandibular/sublingual glands to homologous GTF will be compared with that of parotid fluid. The relative binding constants of parotid IgA and serum IgG will be measured in the functional inhibition assay. The existance of a salivary IgA response to S.mutans GTF in young children will also be investigated. A cross sectional study of the parotid IgA antibody activity to GTF from serotype c strains of S.mutans will be detected. In addition, a longitudinal study will be conducted in which the presence of salivary IgA antibody and the development of S.mutans-containing plaque will be analyzed. An understanding of the development and existence of natural antibody respose to GTF will facilitate the development of a vaccine against dental caries.